Medical imaging techniques that rely on detection of emissions from tracers originating from within the body of a subject are widely used for diagnosis of various diseases and other medically relevant applications. Nuclear physics-based molecular imaging techniques, such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) allow imaging of subjects using radioactive isotopes. For example, SPECT is based on the use of radioisotopes that emit gamma rays and PET is based on the use of radioisotopes that emit positrons, which annihilate electrons to produce gamma rays. In contrast to nuclear imaging techniques, fluorescence based optical imaging techniques do not involve ionizing radiation such as gamma rays. Instead, fluorescence imaging relies on the excitation of fluorescent tracers by an excitation source that results in the absorption of photons by the fluorophores, and the subsequent detection of photons emitted by the fluorescent tracers as they decay from their excited state. A disadvantage of the various imaging techniques that rely on internal tracers, such as PET, SPECT and fluorescence imaging, is that they rely on the use of large scale and expensive scanners for the detection of emissions from these internal tracers, thereby requiring costly visits to radiology clinics.